Process for producing an organsiloxane polymer

ABSTRACT

Process for producing an organosiloxane polymer and novel organosiloxane polymer compositions. The process according to the invention comprises hydrolyzing tetraalkoxysilane monomers in a hydrolysis step; and polymerising said hydrolyzed monomers in a polymerization step by subjecting them to conditions conducive to polymerisation to form an organosiloxane polymer. The hydrolysis step is conducted in a reaction medium comprising an organic compound with hydroxy groups. The invention allows for the synthesis of siloxane polymer compositions suitable for thin-film applications using a high content of tetra- and trifunctional silixane polymer precursors.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is entitled to the benefit of and incorporates byreference essential subject matter disclosed in International PatentApplication No. PCT/FI2008/050092 filed on Feb. 26, 2008 and U.S.Provisional Application No. 60/891,832 filed Feb. 27, 2007.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to organosiloxane polymers suitable forthin film applications. In particular, the invention concerns a novelprocess for producing high-silicon content organosiloxane polymers forthin film applications and to compositions containing such polymers.

2. Description of Related Art

There is a constant demand for decreasing the size of various featuresin semiconductor devices, e.g. integrated circuits (ICs). This demandcreates challenges for the manufacturing processes. Photolithography isan example of a technique commonly used for the production of suchdevices and in particular for creating the patterns that definestructures in ICs. In a lithographic process, a layer of a photoresistmaterial is deposited on a substrate. The photoresist layer isselectively exposed to radiation, such as ultraviolet-light orelectrons, and an exposure tool and mask are used for producing thedesired selective exposure. The patterns in the resist are then createdwhen the wafer undergoes a subsequent “development” step. The areas ofresist that remain after development serve to protect the substrateregions which they cover. Locations from which resist has been removedcan be subjected to a variety of subtractive or additive processes thattransfer the pattern onto the substrate surface.

Usually, siloxane polymers for use in, e.g. spin-on applications areprovided in the form of liquid composition containing the polymer havinga modest degree of polymerization, for example a prepolymer having amolecular weight of about 1,000 to 10,000 g/mol, dissolved or suspendedin an organic solvent.

The method by which the polymer is produced has an impact on theproperties of the organosiloxane polymer, in particular on the use ofthe polymer composition for the production of thin films. Generally, afailure in the synthesis procedure will lead to a drastic reduction inthe deposited film quality. Thus, to mention an example, high silixondioxide content materials can be produced from tri- andtetraalkoxysilane monomers. However, these monomers readily producehigh-molecular weight polymers that have a tendency of gelling duringfilm formation or even during storage.

Therefore, there is a need for improving the synthesis methods of, inparticular, high silicon dioxide materials to provide organosiloxanepolymer compositions that give rise to high-quality thin films.

SUMMARY OF THE INVENTION

It is an aim of the present invention to provide an improved method ofproducing an organosiloxane polymer.

It is a further aim of the invention to provide an organosiloxanepolymer composition.

It is a third aim of the present invention to provide uses ofcompositions produced by the present invention and of the novelcompositions.

In connection with the present invention it has been found that duringthe synthesis of organosiloxane polymers, in particular during thehydrolysis steps, and potentially also the condensation polymerizationsteps, the reactions of the silane precursors are influenced by thesolvents used as reaction medium. In particular, it has been found thatit is possible to control the reactions by incorporating solventscapable of interacting with the precursors or with the hydrolyzedmonomers or of the polymerized molecules or combinations thereof.Examples of such solvents are organic compounds containing hydroxylgroups. It has further been found that hydroxyl compounds haveparticularly beneficial influence on the film-forming properties oforganosiloxane compositions obtained by hydrolysis and condensationpolymerization of silane precursors at least 50 mole-% of which arecomprised of silane monomers containing three or four alkoxy groups.

The present invention therefore comprises a process for producing anorganosiloxane polymer comprising the steps of hydrolyzing siliconmonomers, polymerising said monomers by subjecting them to conditionsconducive to condensation polymerisation to form an organosiloxanepolymer, and recoving said organosiloxane polymer, wherein the step ofhydrolyzing the monomers is conducted in a reaction medium comprising anorganic compound with hydroxyl groups.

Further, it has been found that organosiloxane polymers can beformulated into thin-film forming compositions which contain asignificant amount of an organic solvent with hydroxyl groups and whichexhibit a high solids content (evaporation residue) and where theorganosiloxane polymer has a high silicon content.

More specifically, the present process is characterized by what isstated in the characterizing part of claim 1.

The composition according to the present invention is characterized bywhat is stated in the characterizing part of claim.

The invention provides considerable advantages. Thus, the synthesismethod described in the present invention makes it possible tosynthesize siloxane polymer compositions that would under usualhydrolysis and condensation polymerization conditions result in materialthat would not be possible to be process able through the liquid phasedeposition techniques. The method described allows for the use of a highcontent of tetra- and trifunctional silixane polymer precursors.

The various applications of the invention will be examined below.Summarizing, it can here be noted that the present coating(film-forming) compositions according to the invention can be used forforming an optical or electrical thin film coating on a substrate, forforming anti-reflection coatings, for forming a chemical and dry etchingstop layer in lithographic processing, for forming a protective coatingin an organic light emitting device, and for forming an efficiencyenhancing layer in a solar cell. Further, the invention can be used forforming a high index material in an optical thin film filter and forforming an optical diffractive grating and a hybrid thin filmdiffractive grating by embossing, holography lithography andnano-imprinting of the thin film.

Next the invention will be examined more closely with the aid of adetailed description and a number of working examples.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

As discussed above, according to one aspect, the present invention isbased on the finding that by incorporating an organic compoundcontaining hydroxyl groups, capable of interacting with the hydrolyzingmonomers, it is possible to influence the chemical character of thepolymer formed by condensation.

According to one particularly preferred embodiment, the content oftrifunctional or, preferably, tetra-functional alkoxide (alkoxysilane)residues in the polymer is at least 50 mole-%, preferably at least 60mole-% and in particular at least 70 mole-% or even higher. Theseresidues can be derived from, e.g. tri(lower alkoxy)silanes ortetra(lower alkoxy)silanes, such as ethoxysilane or tetramethoxysilaneor mixtures thereof. By using a large portion of these compounds, thesilicon dioxide content of the final deposited film can be maximized.Naturally, it is also possible to use precursors, i.e. silane monomershaving organic functionalities, in the precursor procedure.

Generally the synthesis of the siloxane polymer composition consists oftwo steps: In the first synthesis step (in the following also called thehydrolysis step) the precursor molecules are hydrolyzed in presence ofwater and a catalyst, such as hydrochloric acid or another mineral ororganic acid, and in the second step (the polymerization step), themolecular weight of the material is increased by condensationpolymerization.

The water used in the hydrolysis step has typically a pH of less than 7,preferably less than 6, in particular less than 5.

The synthesis is carried out in a synthesis solvent or a mixture ofsolvents.

As discussed above, the solvent or solvent mixtures employed has/have animpact on the hydrolysis and condensation reactions during thesynthesis. The solvents can roughly be characterized as being inert (orinactive) and active solvents with respect to their interaction with thehydrolysis and polymerisation reactions, respectively.

According to one embodiment, the reaction medium of the hydrolysis stepcomprises 5 to 95 mole-%, preferably 10 to 80 mole-%, of the organiccompound containing hydroxyl groups, and 95 to 5 mole-%, in particular90 to 20 mole-% of water.

The reaction medium of the hydrolysis step may comprise also a secondorganic solvent (the organic compound with hydroxyl groups being the“first” organic solvent). This second organic solvent is selected fromthe group of aliphatic and aromatic hydrocarbons, aliphatic or aromaticethers, aliphatic or aromatic esters and mixtures thereof.

According to a preferred embodiment, the reaction medium comprises 5 to90 mole-%, in particular about 20 to 80 mole-% and in particular about40 to 75 mole-% of a second organic solvent. A particularly preferredembodiment provides for the use of a reaction medium which comprises atleast 50 mole-% of the second organic solvent, a minimum of 10 mole-% ofthe organic hydroxyl compound and a minimum of 10 mole-% water.

Typically, the second organic solvent is capable of dissolving thehydrolyzed monomer.

The organic hydroxy compound and the first organic solvent are misciblewith each other.

The organic hydroxy compound is preferably an alcohol having the formulaR⁵—OH wherein R⁵ stands for

a linear or branched or cyclic alkyl having 1 to 10 carbon atoms, saidalkyl optionally being substituted with one or several hydroxy groups,halogen groups, thiol groups, carboxylic acid groups, and aryl groups;oran aryl group having 6 to 12 carbon atoms, which aryl group isoptionally substituted with one or several hydroxy groups, halogengroups, thiol groups, carboxylic acid groups, and aryl groups.

In particular, the organic hydroxyl compound is selected from the groupof primary, secondary and tertiary alcohols. Typical examples aremethanol, ethanol, propanol, isopropanol, n-butanol, tert-butanol, amylalcohol, as well as bifunctional alcohols (diols) such as ethanodiol(ethelene glycol), propandiol (propylene glycol) and derivativesthereof.

There can be a mixture of water and an alcohol, the weight ratio ofwater-to-alcohol being about 5:95 to 95:5, preferably about 10:90 to90:10, in particular 20:80 to 80:20.

Based on the above, suitable solvents for the synthesis are, forexample, acetone, tetrahydrofuran (THF), toluene, 2-propanol, methanol,ethanol, propylene glycol monomethyl ether, propylene glycol propylether, methyl-tert-butylether (MTBE), propyleneglycolmonomethyletheracetate (PGMEA), propyleneglycolmonomethylether PGME and propyleneglycol propyl ether (PnP).

In the first synthesis step, the precursor, water, catalyst, synthesissolvent(s) mixture are refluxed for 0.1 to 24 hours, generally about 0.2to 15 hours, in particular about 1-5 hours. After this time, thesynthesis solvent(s), water and other by-products, such as alcohols, areremoved. This is performed by distillation.

If inert synthesis solvents such as acetone are used during hydrolysis(cf. Example 1) and when the intermediate product is completely dried bydistillation, i.e. when all solvents and by-product and water areremoved, it is not readily possible to dissolve the material in any ofthe processing solvents. This is typically the case with high siliconcontent compositions (high concentration of tetraalkoxy silane monomersin the reaction mixture). Accordingly, in a preferred embodiment,solvent exchange is carried out during the process (cf. Example 2). Insuch a solvent exchange step, the second organic solvent is changed fora third organic solvent which has a higher boiling point that thesecond. Thus, acetone can be change for PGMEA, PGME, or PnP, to mentionsome examples.

A further preferred embodiment comprises the use of active solventduring the synthesis. This results usually in a composition that can bedried to dryness by using distillation and then easily redissolved agingto a processing or further synthesis solvent.

In the second synthesis step, i.e. the condensation polymerization step,the material is further refluxed in a solvent or a solvent, preferablyhaving a higher boiling point than the solvent or solvent mixture usedfor hydrolysis for a reaction time of approx. 0.1 to 24 hours,preferably 0.2 to 15 hours, in particular about 1-5 hours. During thesecond synthesis step, the molecular weight of the material is increaseddue to condensation polymerization. Conventionally, the averagemolecular weight of the polymer is about 500 to 50,000 g/mol, inparticular about 1,000 to 10,000 g/mol, preferably about 2,000 to 8,000g/mol, and advantageously about 3,000 to 6,000 g/mol, although these areno absolute limits.

After the second step, the reaction by-products, such as water andalcohols, may be removed using distillation. Also the used higherboiling point solvent(s) can be changed to another solvent that isrequired to be used in the deposition process. Mixtures of two or moresolvents can also be used as processing solvent.

During the synthesis it is possible to use certain stabilizer solventsor additives or they can be added at the end of the synthesis to thefinal synthesized material to improve material shelf-life.

As will appear from the above, the organic hydroxy compound ispreferably present both during the hydrolysis and the polymerization ofthe monomer.

After synthesis, the organosiloxane polymer can be recovered in thereaction medium.

The synthesized material is then diluted using a proper solvent orsolvent combination to result in desirable film thickness. According toa preferred embodiment, the organosiloxane polymer is formulated into acomposition comprising at least about 20 mole-% of an organic hydroxylcompound.

Film thicknesses may range e.g. from 5 nm to 10 μm. Various methods ofproducing thin films are described in U.S. Pat. No. 7,094,709, thecontents of which are herewith incorporated by reference.

In the above process, various silane monomers, and in particularcombinations of silane monomers, can be used as precursors of thepresent organosiloxane polymers.

According to one embodiment, the process according to the inventioncomprises hydrolyzing and polymerizing a monomer according to either orboth of formulas I and II:

R¹ _(a)SiX_(4-a)  I

and

R² _(b)SiX_(4-b)  II

-   wherein R¹ and R² are independently selected from the group    consisting of hydrogen, linear and branched alkyl and cycloalkyl,    alkenyl, alkynyl, (alk)acrylate, epoxy and alkoxy and aryl having 1    to 6 rings;    -   each X represents independently a hydrolysable group or a        hydrocarbon residue; and    -   a and b is an integer 1 to 3.

Further, in combination with monomers of formula I or II or as such atleast one monomer corresponding to Formula III can be employed:

R³ _(c)SiX_(4-c)  III

-   wherein R³ stands for hydrogen, alkyl or cycloalkyl which optionally    carries one or several substituents, or alkoxy;    -   each X represents independently a hydrolysable group or a        hydrocarbon residue having the same meaning as above; and    -   c is an integer 1 to 3.

In any of the formulas above, the hydrolysable group is in particular analkoxy group (cf. formula IV).

As discussed above, the present invention provides for the production oforganosiloxane polymers using tri- or tetraalkoxysilane as thepredominant monomer, said tri- or tetraalkoxysilane making up at least60 mole-%, in particular at least 70 mole-%, suitably at least 80 mole-%(even up to 100 mole-%) of the total amount of monomers. The alkoxygroups of the silane can be identical or different and preferablyselected from the group of radicals having the formula

O—R⁴  IV

wherein R⁴ stands for a linear or branched alkyl group having 1 to 10,preferably 1 to 6 carbon atoms, and optionally exhibiting one or twosubstitutents selected from the group of halogen, hydroxyl, vinyl, epoxyand allyl.

Particularly suitable monomers are selected from the group oftriethoxysilane, tetraethoxysilane, methyltriethoxysilane,ethyltriethoxysilane, n-butyltriethoxysilane, methyldiethoxyvinylsilane,dimethyldiethoxysilane, phenyltrimethoxysilane, andphenantrene-9-triethoxysilane and mixtures thereof.

According to one embodiment, at least 50 mole-% of the monomers beingselected from the group of tetraethoxysilane, methyltriethoxysilane,ethyltriethoxysilane, n-butyltriethoxysilane, methyldiethoxyvinylsilaneand dimethyldiethoxysilane and mixtures thereof.

The final anti-reflective coating film thickness has to be optimizedaccording for each device fabrication process. When using, for example,when PGMEA is employed as solvent for the synthesis, in one or both ofthe above-described the synthesis steps, it is not necessary to changethe solvent for the final material, since PGMEA is regularly used alsoas a processing solvent in the semiconductor industry. This makes thesynthesis procedure of the material easier and less time consuming.

The present invention provides novel organosiloxane polymer composition,comprising

an organosiloxane polymer formed by a partially cross-linked siloxanebackbone comprising residues derived from tetraalkoxysilane monomers,said residues making up at least 50 mole-% of the siloxane backbone; anda solvent mixture, comprising at least 30 mole-% of an organic hydroxylcompound.

The siloxane is partially cross-linked, the average molecular weightbeing about 500 to 50,000 g/mol, in particular about 1,000 to 10,000g/mol, preferably about 2,000 to 8,000 g/mol, and advantageously about3,000 to 6,000 g/mol.

According to one embodiment, the solvent mixture is essentiallynon-aqueous.

The solids concentration of the composition is at least 15 weight-%.Further it is preferred that the organosiloxane polymer contains atleast 60 mole-%, in particular at least 70 mole-%, residues derived fromtetraalkoxysilane monomers.

The other components of the solvent mixture can be the same as above.According to an interesting embodiment, the solvent mixture comprises atleast 30 mole-%, preferably 30 to 75 mole-% of an alcohol or similarhydroxyl compound and 70 to 25 mole-% of at least one other organicsolvent selected from the group of aliphatic and aromatic hydrocarbons,aliphatic or aromatic ethers, aliphatic or aromatic esters and mixturesthereof.

As briefly discussed above, the present materials have a great number ofinteresting new applications. Examples include:

A. Optical and electrical coatingsB. High dielectric constant (high-k) gate oxides and interlayer high-kdielectricsC. ARC (anti-reflection) coatingsD. Etch and CMP stop layersE. Protection and sealing (OLED etc.)F. Organic solar cellsG. Optical thin film filtersH. Optical diffractive gratings and hybrid thin film diffractive gratingstructuresI. High refractive index abrasion resistant coatings

The following examples will elucidate the invention:

Example 1

Tetraethoxysilane (300.00 g, 100 mol %) was weighed to a round bottomflask. 300.0 g of (Propyleneglycol monomethyl ether) PGME was added tothe round bottom flask. 103.68 g of water (0.01 M HCl) was added to thereaction flask within 5 min, while constantly stirring the reactionmixture using a magnetic stirrer. After this the reaction mixture wasstirred at RT for 15 min and refluxed for 5 hours using electric mantel.After refluxing a solvent exchange procedure was performed (206 g ofPGME was added). After the solvent exchange the material solution wasrefluxed at 120 C for 2 hours. After the 2 hour refluxing step thematerial is ready to use after dilution and filtration. The material wasdiluted (by adding PGME) to 20% solid content and filtrated using 0.1 μmPTFE filter.

As can be seen from the above example this composition is synthesized byusing only tetraethoxysilane as precursor molecule in the synthesisprocess of the polymer. This composition will result in very highsilicon content in the final material. This can be calculated astheoretical silicon content (%) value. The calculation is based on theatom weights of the final compositions. As an example, for pure SiO₂ thesilicon content is 46.7% (28.09/60.09*100%=46.7%). If triethoxysilane isused as starting material even higher silicon content value can beachieved. If the synthesis is done for example in an inert solvent, suchas acetone, and all the solvent is evaporated away after the 5 hhydrolysis the material would not possibly anymore to be dissolved inany solvent.

So one way to prevent this to use solvent exchange procedure to examplePGMEA or PGME as illustrated in the following examples. This way we areable to make a working siloxane polymer solution for deposition.Furthermore, it is possible to use an “active” solvent(s) (or solventmixtures, active or inert solvents) during the synthesis procedure (suchas alcohols like isopropanol, PGME, PnP etc.) to control the hydrolysisand condensation reactions. As illustrated in Example 1 PGME is used assynthesis solvent.

After the hydrolysis step it would be possible to evaporate thesynthesis solvents completely way and still be able to dissolve thematerial into a processing solvent to make a material composition forfilm deposition. Obviously in this case it is possible to use a solventexchange to change the processing solvent to another solvent such asPGMEA or PnP if it is preferred. The solvent exchange procedure willresult in a more repeatable synthesis process.

To modify the composition (silicon content or other physical, optical,mechanical or chemical properties) it is possible to add in organicfunctionalities bearing precursor molecules in the synthesis. Examplesare silanes having aromatic substitutents or other chromophoricsubstitutents. Furthermore it is possible to use some photoactivefunctionalities in the precursors that allow one to use thermal orirradiation activated polymerization during processing. Functionalitiesof this kind include epoxy, vinyl and allyl groups. This includesmoieties that allow one to make both positive lithographic tone andnegative lithographic tone siloxane polymer compositions.

The example below illustrate some examples of the synthesizedcompositions. These are just illustrative examples and the presentinvention is not restricted to these cases that are represented below.

Example 2

Phenyltrimethoxysilane (26.03 g, 13 mol %), tetraethoxysilane (119.97 g,57 mol %) and methyltriethoxysilane (53.98 g, 30 mol %) were weighed toa round bottom flask. 100.0 g of (Propyleneglycol monomethyl ether) PGMEwas added to the round bottom flask. 64.85 g of water (0.01 M HCl) wasadded to the reaction flask within 5 min, while constantly stirring thereaction mixture using a magnetic stirrer. After this the reactionmixture was stirred at RT for 27 min and refluxed for 5 hours usingelectric mantel. After refluxing a solvent exchange procedure wasperformed from PGME to PGMEA (230 g of PGMEA was added). After thesolvent exchange step the material is ready to use after dilution andfiltration. The material was diluted (by adding PGMEA) to 20% solidcontent and filtrated using 0.1 μm PTFE filter.

Example 3

Phenyltrimethoxysilane (1.60 g, 5 mol %), tetraethoxysilane (26.81 g, 80mol %) and Phenanthrene-9-triethoxysilane (8.24 g, 15 mol %) wereweighed to a round bottom flask. 73.3 g of acetone was added to theround bottom flask. 10.75 g of water (0.01 M HCl) was added to thereaction flask within 5 min, while constantly stirring the reactionmixture using a magnetic stirrer. After this the reaction mixture wasstirred at RT for 27 min and refluxed for 5 hours using electric mantel.After the refluxing, most of the acetone was removed from the reactionmixture using a rotary evaporator (pressure 350->250 mbar, t(bath)=50°C.). After most of the acetone was removed, 72 g of PGMEA was added tothe flask. The reaction mixture was evaporated further in the rotaryevaporator (pressure 45 mbar, t(bath)=50° C., 1 hour) after PGMEAaddition to perform a solvent exchange. After the solvent exchange thematerial solution was refluxed at 120 C for 2 hours. After the 2 hourrefluxing step the material is ready to use after dilution andfiltration. The material was diluted (by adding PGMEA) to 20% solidcontent and filtrated using 0.1 μm PTFE filter.

Example 4

Phenyltrimethoxysilane (4.80 g, 5 mol %), tetraethoxysilane (85.47 g, 85mol %) and Phenanthrene-9-triethoxysilane (16.47 g, 10 mol %) wereweighed to a round bottom flask. 213.48 g of acetone was added to theround bottom flask. 33.48 g of water (0.01 M HCl) was added to thereaction flask within 4 min, while constantly stirring the reactionmixture using a magnetic stirrer. After this the reaction mixture wasstirred at RT for 26 min and refluxed for 5 hours using electric mantel.After the refluxing, most of the acetone was removed from the reactionmixture using a rotary evaporator (pressure 400->200 mbar, t(bath)=50°C.). After most of the acetone was removed, 105 g of PGMEA was added tothe flask. The reaction mixture was evaporated further in the rotaryevaporator (pressure 45 mbar, t(bath)=50° C., 1 hour) after PGMEAaddition to perform a solvent exchange. After the solvent exchange thematerial solution was refluxed at 120 C for 2 hours. After the 2 hourrefluxing step the material is ready to use after dilution andfiltration. The material was diluted (by adding PGMEA) to 20% solidcontent and filtrated using 0.1 μm PTFE filter.

Example 5

The same composition as in Example 3 was produced on a larger scalereaction as follows:

Phenyltrimethoxysilane (80 g, 5 mol %), tetraethoxysilane (1340.5 g, 80mol %) and Phenanthrene-9-triethoxysilane (412 g, 15 mol %) were weighedto a round bottom flask. 3665.0 g of acetone was added to the roundbottom flask. 550.74 g of water (0.01 M HCl) was added to the reactionflask within 5 min, while constantly stirring the reaction mixture usinga magnetic stirrer. After this the reaction mixture was stirred at RTfor 27 min and refluxed for 5 hours using electric mantel. After therefluxing, most of the acetone was removed from the reaction mixtureusing a rotary evaporator (pressure 350->250 mbar, t(bath)=50° C.).After most of the acetone was removed, 600 g of PGMEA was added to theflask. The reaction mixture was evaporated further in the rotaryevaporator (pressure 45 mbar, t(bath)=50° C., 1 hour) after PGMEAaddition to perform a solvent exchange. After the solvent exchange thematerial solution was refluxed at 120 C for 2 hours. After the 2 hourrefluxing step the material is ready to use after dilution andfiltration. The material was diluted (by adding PGMEA) to 20% solidcontent and filtrated using 0.1 μm PTFE filter.

Example 6

Phenyltrimethoxysilane (80 g, 5 mol %), tetraethoxysilane (1340.5 g, 80mol %) and Phenanthrene-9-triethoxysilane (412 g, 15 mol %) were weighedto a round bottom flask. 3665.0 g of acetone was added to the roundbottom flask. 550.74 g of water (0.01 M HCl) was added to the reactionflask within 5 min, while constantly stirring the reaction mixture usinga magnetic stirrer. After this the reaction mixture was stirred at RTfor 27 min and refluxed for 5 hours using electric mantel. After therefluxing, most of the acetone was removed from the reaction mixtureusing a rotary evaporator (pressure 350->250 mbar, t(bath)=50° C.).After most of the acetone was removed, 600 g of PGMEA was added to theflask. The reaction mixture was evaporated further in the rotaryevaporator (pressure 45 mbar, t(bath)=50° C., 1 hour) after PGMEAaddition to perform a solvent exchange. After the solvent exchange thematerial solution was refluxed at 120 C for 2 hours. After the 2 hourrefluxing step the material is ready to use after dilution andfiltration. The material was diluted (by adding PGMEA) to 25% solidcontent.

Example 7

Phenyltrimethoxysilane (80 g, 5 mol %), tetraethoxysilane (1340.5 g, 80mol %) and Phenanthrene-9-triethoxysilane (412 g, 15 mol %) were weighedto a round bottom flask. 3665.0 g of acetone was added to the roundbottom flask. 550.74 g of water (0.01 M HCl) was added to the reactionflask within 5 min, while constantly stirring the reaction mixture usinga magnetic stirrer. After this the reaction mixture was stirred at RTfor 27 min and refluxed for 5 hours using electric mantel. After therefluxing, most of the acetone was removed from the reaction mixtureusing a rotary evaporator (pressure 350->250 mbar, t(bath)=50° C.).After most of the acetone was removed, 600 g of PGMEA was added to theflask. The reaction mixture was evaporated further in the rotaryevaporator (pressure 45 mbar, t(bath)=50° C., 1 hour) after PGMEAaddition to perform a solvent exchange. After the solvent exchange thematerial solution was refluxed at 120 C for 2 hours. After the 2 hourrefluxing step the material is ready to use after dilution andfiltration. The material was diluted (by adding PGMEA) to 20% solidcontent and filtrated using 0.1 μm PTFE filter. After adding the PGMEAthe material solution was further diluted by PGME to result in 11% finalsolid content and 1:1 PGMEA:PGME solution.

Example 8

Phenyltrimethoxysilane (13.10 g, 5 mol %), tetraethoxysilane (219.99 g,80 mol %) and Phenanthrene-9-triethoxysilane (67.58 g, 15 mol %) wereweighed to a round bottom flask. 300.66 g of PGME was added to the roundbottom flask. 90.29 g of water (0.01 M HCl) was added to the reactionflask within 5 min, while constantly stirring the reaction mixture usinga magnetic stirrer. After this the reaction mixture was stirred at RTfor 15 min and refluxed for 5 hours using electric mantel. Afterrefluxing a solvent exchange procedure was performed from PGME to PGME(203 g of PGME was added). After the solvent exchange the materialsolution was refluxed at 120 C for 2 hours. After the 2 hour refluxingstep the material is ready to use after dilution and filtration. Thematerial was diluted (by adding PGME) to 20% solid content and filtratedusing 0.1 μm PTFE filter.

Example 9

Phenyltrimethoxysilane (44.62 g, 15 mol %), tetraethoxysilane (250.00 g,80 mol %) and Phenanthrene-9-triethoxysilane (25.62 g, 5 mol %) wereweighed to a round bottom flask. 320.24 g of IPA/PGME mixture (1:1) wasadded to the round bottom flask. 102.60 g of water (0.01 M HCl) wasadded to the reaction flask within 5 min, while constantly stirring thereaction mixture using a magnetic stirrer. After this the reactionmixture was stirred at RT for 15 min and refluxed for 5 hours usingelectric mantel. After refluxing a solvent exchange procedure wasperformed from IPA/PGME mixture to PGME (200 g of PGME was added). Afterthe solvent exchange the material solution was refluxed at 120 C for 2hours. After refluxing the material is ready to use after dilution andfiltration. The material was diluted (by adding PGME) to 20% solidcontent and filtrated using 0.1 μm PTFE filter.

Example 10

Phenyltrimethoxysilane (25.05 g, 10 mol %), tetraethoxysilane (150.00 g,57 mol %), Phenanthrene-9-triethoxysilane (12.95 g, 3 mol %) andmethyltriethoxysilane (67.57 g, 30 mol %) were weighed to a round bottomflask. 255.57 g of PGME was added to the round bottom flask. 81.16 g ofwater (0.01 M HCl) was added to the reaction flask within 5 min, whileconstantly stirring the reaction mixture using a magnetic stirrer. Afterthis the reaction mixture was stirred at RT for 15 min and refluxed for5 hours using electric mantel. After refluxing a solvent exchangeprocedure was performed from PGME to PGME (200 g of PGME was added).After the solvent exchange the material solution was refluxed at 120 Cfor 2 hours. After refluxing the material is ready to use after dilutionand filtration. The material was diluted (by adding PGME) to 20% solidcontent and filtrated using 0.1 μm PTFE filter.

Example 11

Phenyltrimethoxysilane (28.43 g, 10 mol %), tetraethoxysilane (230.0 g,77 mol %), Phenanthrene-9-triethoxysilane (14.69 g, 3 mol %) andtriethoxysilane (23.55 g, 10 mol %) were weighed to a round bottomflask. 296.67 g of IPA/PGME mixture (1:1) was added to the round bottomflask. 97.25 g of water (0.01 M HCl) was added to the reaction flaskwithin 5 min, while constantly stirring the reaction mixture using amagnetic stirrer. After this the reaction mixture was stirred at RT for15 min and refluxed for 5 hours using electric mantel. After refluxing asolvent exchange procedure was performed from IPA/PGME mixture to PGME(202 g of PGME was added). After the solvent exchange the materialsolution was refluxed at 120 C for 2 hours. After refluxing step thematerial is ready to use after dilution and filtration. The material wasdiluted (by adding PGME) to 20% solid content and filtrated using 0.1 μmPTFE filter.

Example 12

Phenyltrimethoxysilane (8.39 g, 5 mol %), tetraethoxysilane (140.86 g,80 mol %) and Phenanthrene-9-triethoxysilane (43.27 g, 15 mol %) wereweighed to a round bottom flask. 192.51 g of PGME was added to the roundbottom flask. 57.81 g of water (0.01 M HCl) was added to the reactionflask within 5 min, while constantly stirring the reaction mixture usinga magnetic stirrer. After this the reaction mixture was stirred at RTfor 15 min and refluxed for 5 hours using electric mantel. Afterrefluxing a solvent exchange procedure was performed from PGME to PGME(230 g of PGME was added). After the solvent exchange the materialsolution was refluxed at 120 C for 2 hours. After the 2 hour refluxingstep the material is ready to use after dilution and filtration. Thematerial was diluted (by adding PGME) to 20% solid content and filtratedusing 0.1 μm PTFE filter. This solution was further diluted using PnP(Propylene glycol propyl ether) to result in 11% solution (1:1,PGME:PnP).

Example 13

Phenyltrimethoxysilane (8.39 g, 5 mol %), tetraethoxysilane (140.86 g,80 mol %) and Phenanthrene-9-triethoxysilane (43.27 g, 15 mol %) wereweighed to a round bottom flask. 192.51 g of PGME was added to the roundbottom flask. 57.81 g of water (0.01 M HCl) was added to the reactionflask within 5 min, while constantly stirring the reaction mixture usinga magnetic stirrer. After this the reaction mixture was stirred at RTfor 15 min and refluxed for 5 hours using electric mantel. Afterrefluxing a solvent exchange procedure was performed from PGME to PGME(230 g of PGME was added). After the solvent exchange the materialsolution was refluxed at 120 C for 2 hours. After the 2 hour refluxingstep the material is ready to use after dilution and filtration. Thematerial was diluted (by adding PGME) to 20% solid content and filtratedusing 0.1 μm PTFE filter. This solution was further diluted using NPA(n-propyl acetate) to result in 11% solution (1:1, PGME:NPA).

Example 14

Phenyltrimethoxysilane (8.39 g, 5 mol %), tetraethoxysilane (140.86 g,80 mol %) and Phenanthrene-9-triethoxysilane (43.27 g, 15 mol %) wereweighed to a round bottom flask. 192.51 g of PGME was added to the roundbottom flask. 57.81 g of water (0.01 M HCl) was added to the reactionflask within 5 min, while constantly stirring the reaction mixture usinga magnetic stirrer. After this the reaction mixture was stirred at RTfor 15 min and refluxed for 5 hours using electric mantel. Afterrefluxing a solvent exchange procedure was performed from PGME to PGME(230 g of PGME was added). After the solvent exchange the materialsolution was refluxed at 120 C for 2 hours. After the 2 hour refluxingstep the material is ready to use after dilution and filtration. Thematerial was diluted (by adding PGME) to 20% solid content and filtratedusing 0.1 μm PTFE filter. This solution was further diluted using NBA(n-butyl acetate) to result in 11% solution (1:1, PGME:NBA).

Example 15

Phenyltrimethoxysilane (13.10 g, 5 mol %), tetraethoxysilane (220.00 g,80 mol %) and Phenanthrene-9-triethoxysilane (67.58 g, 15 mol %) wereweighed to a round bottom flask. 601.32 g of acetone was added to theround bottom flask. 90.29 g of water (0.01 M HCl) was added to thereaction flask within 5 min, while constantly stirring the reactionmixture using a magnetic stirrer. After this the reaction mixture wasstirred at RT for 15 min and refluxed for 5 hours using electric mantel.After refluxing a solvent exchange procedure was performed from acetoneto PGMEA (380 g of PGMEA was added). After the solvent exchange thematerial solution was refluxed at 120 C for 2 hours. After the 2 hourrefluxing step the material is ready to use after dilution andfiltration. The material was diluted (by adding PGMEA) to 20% solidcontent and filtrated using 0.1 μm PTFE filter. This solution wasfurther diluted using PnP to result in 11% solution (1:1, PGME:PnP).

Example 16

Phenyltrimethoxysilane (13.10 g, 5 mol %), tetraethoxysilane (220.00 g,80 mol %) and Phenanthrene-9-triethoxysilane (67.58 g, 15 mol %) wereweighed to a round bottom flask. 601.32 g of acetone was added to theround bottom flask. 90.29 g of water (0.01 M HCl) was added to thereaction flask within 5 min, while constantly stirring the reactionmixture using a magnetic stirrer. After this the reaction mixture wasstirred at RT for 15 min and refluxed for 5 hours using electric mantel.After refluxing a solvent exchange procedure was performed from acetoneto PGMEA (380 g of PGMEA was added). After the solvent exchange thematerial solution was refluxed at 120 C for 2 hours. After the 2 hourrefluxing step the material is ready to use after dilution andfiltration. The material was diluted (by adding PGMEA) to 20% solidcontent and filtrated using 0.1 μm PTFE filter. This solution wasfurther diluted using NPA to result in 11% solution (1:1, PGME:NPA).

Example 17

Phenyltrimethoxysilane (13.10 g, 5 mol %), tetraethoxysilane (220.00 g,80 mol %) and Phenanthrene-9-triethoxysilane (67.58 g, 15 mol %) wereweighed to a round bottom flask. 601.32 g of acetone was added to theround bottom flask. 90.29 g of water (0.01 M HCl) was added to thereaction flask within 5 min, while constantly stirring the reactionmixture using a magnetic stirrer. After this the reaction mixture wasstirred at RT for 15 min and refluxed for 5 hours using electric mantel.After refluxing a solvent exchange procedure was performed from acetoneto PGMEA (380 g of PGMEA was added). After the solvent exchange thematerial solution was refluxed at 120 C for 2 hours. After the 2 hourrefluxing step the material is ready to use after dilution andfiltration. The material was diluted (by adding PGMEA) to 20% solidcontent and filtrated using 0.1 μm PTFE filter. This solution wasfurther diluted using NBA to result in 11% solution (1:1, PGME:NBA).

While the present invention has been illustrated and described withrespect to a particular embodiment thereof, it should be appreciated bythose of ordinary skill in the art that various modifications to thisinvention may be made without departing from the spirit and scope of thepresent invention.

1. A process for producing an organosiloxane polymer comprisinghydrolyzing tri- and tetraalkoxysilane monomers in a hydrolysis step;and polymerising said hydrolyzed monomers in a polymerization step bysubjecting them to conditions conducive to polymerisation to form anorganosiloxane polymer; wherein the hydrolysis step is conducted in areaction medium comprising an organic compound with hydroxy groups. 2.The process according to claim 1, comprising producing an organosiloxanepolymer containing at least 50 mole-%, preferably at least 60 mole-%, inparticular at least 70 mole-%, advantageously at least 80 mole-%,residues derived from tetraalkoxysilane monomers.
 3. The processaccording to claim 1, wherein the reaction medium of the hydrolysis stepcomprises 5 to 95 mole-%, preferably 10 to 80 mole-%, of the organiccompound containing hydroxyl groups.
 4. The process according to claim3, wherein the reaction medium of the hydrolysis step comprises a secondorganic solvent.
 5. The process according to claim 4, wherein the secondorganic solvent is selected from the group of aliphatic and aromatichydrocarbons, aliphatic or aromatic ethers, aliphatic or aromatic estersand mixtures thereof.
 6. The process according to claim 4, wherein thereaction medium comprises 5 to 90 mole-%, in particular about 20 to 80mole-% and in particular about 40 to 75 mole-% of the second organicsolvent.
 7. The process according to claim 1, wherein the reactionmedium comprises 1 to 30, in particular 5 to 25 mole-% water.
 8. Theprocess according to claim 1, wherein the reaction medium comprises atleast 50 mole-% of the second organic solvent, a minimum of 10 mole-% ofthe organic hydroxyl compound and a minimum of 10 mole-% water.
 9. Theprocess according to claim 1, wherein the second organic solvent iscapable of dissolving the hydrolyzed monomer.
 10. The process accordingto claim 1, wherein the organic hydroxy compound and the first organicsolvent are miscible with each other.
 11. The process according to claim1, wherein the organic hydroxy compound is an alcohol having the formulaR⁵—OH wherein R⁵ stands for a linear or branched or cyclic alkyl having1 to 10 carbon atoms, said alkyl optionally being substituted with oneor several hydroxy groups, halogen groups, thiol groups, carboxylic acidgroups, and aryl groups; or an aryl group having 6 to 12 carbon atoms,which aryl group is optionally substituted with one or several hydroxygroups, halogen groups, thiol groups, carboxylic acid groups, and arylgroups.
 12. The process according to claim 1, wherein the second organicsolvent is changed for a third solvent.
 13. The process according toclaim 12, wherein the second organic solvent is changed for a thirdorganic solvent.
 14. The process according to claim 8, wherein thesecond organic solvent is changed for a third solvent after hydrolysisof the monomers.
 15. The process according to claim 14, wherein thesecond organic solvent is changed for a third solvent beforepolymerization of the hydrolyzed monomers.
 16. The process according toclaim 13, wherein water is removed before the polymerization step. 17.The process according to claim 1, wherein water used in the hydrolysisstep has a pH of less than 7, preferably less than 6, in particular lessthan
 5. 18. The process according to claim 1, wherein the organichydroxy compound is present both during the hydrolysis and thepolymerization of the monomer.
 19. The process according to claim 1,comprising recovering the organosiloxane polymer, wherein said polymeris recovered in the reaction medium.
 20. The process according to claim1, comprising recovering the organosiloxane polymer, wherein saidpolymer is formulated into a composition comprising at least about 20mole-% of an organic hydroxyl compound.
 21. The process according toclaim 1, comprising hydrolyzing and polymerizing a monomer according toeither or both of formulas I and II:R¹ _(a)SiX_(4-a)  IandR² _(b)SiX_(4-b)  II wherein R¹ and R² are independently selected fromthe group consisting of hydrogen, linear and branched alkyl andcycloalkyl, alkenyl, alkynyl, (alk)acrylate, epoxy and alkoxy and arylhaving 1 to 6 rings; each X represents independently a hydrolysablegroup or a hydrocarbon residue; and a and b is an integer 1 to
 3. 22.The process according to claim 1, comprising using at least one monomercorresponding to Formula III:R³ _(c)SiX_(4-c)  III wherein R³ stands for hydrogen, alkyl orcycloalkyl which optionally carries one or several substituents, oralkoxy; each X represents independently a hydrolysable group or ahydrocarbon residue having the same meaning as above; and c is aninteger 1 to
 3. 23. The process according to claim 1, comprising usingmonomers selected from the group of triethoxysilane, tetraethoxysilane,methyltriethoxysilane, ethyltriethoxysilane, n-butyltriethoxysilane,methyldiethoxyvinylsilane, dimethyldiethoxysilane,phenyltrimethoxysilane, and phenantrene-9-triethoxysilane and mixturesthereof, at least 50 mole-% of the monomers being selected from thegroup of tetraethoxysilane, methyltriethoxysilane, ethyltriethoxysilane,n-butyltriethoxysilane, methyldiethoxyvinylsilane anddimethyldiethoxysilane and mixtures thereof.
 24. The process accordingto claim 1, comprising using tetraalkoxysilane as a monomer, whereinsaid alkoxy groups of the silane being identical or different andselected from the group of radicals having the formula —O—R⁴, wherein R⁴stands for a linear or branched alkyl group having 1 to 10, preferably 1to 6 carbon atoms, and optionally exhibiting one or two substitutensselected from the group of halogen, hydroxyl, vinyl, epoxy and allyl.25. The process according to claim 21, wherein the hydrolysable group isan alkoxy group.
 26. The process according to claim 1, wherein theorganic hydroxyl compound is selected from the group of primary,secondary and tertiary alcohols.
 27. The process according to claim 1,wherein the silicon content of the organosiloxane polymer is at least 20mole-%, preferably at least 25 mole-%, in particular at least 30 mole-%,suitably at least 35 mole-%, advantageously even 40 mole-% or more. 28.An organosiloxane polymer composition, comprising an organosiloxanepolymer formed by a partially cross-linked siloxane backbone comprisingresidues derived from tri- or tetraalkoxysilane monomers orcombinations, said residues making up at least 50 mole-% of the siloxanebackbone; and a solvent mixture, comprising at least 30 mole-% of anorganic hydroxyl compound.
 29. The composition according to claim 28,wherein cross-linked siloxane has an average molecular weight of about500 to 20,000 g/mol, in particular about 1,000 to 10,000 g/mol.
 30. Thecomposition according to claim 28, having a solids concentration of atleast 15 weight-%.
 31. The composition according to claim 28, whereinthe organosiloxane polymer contains at least 60 mole-%, in particular atleast 70 mole-%, residues derived from tetraalkoxysilane monomers.
 32. Athin film formed from a composition according to claim
 28. 33. The useof a composition produced by a process according to claim 1 for opticaland electrical coatings; high dielectric constant (high-k) gate oxidesand interlayer high-k dielectrics; ARC (anti-reflection) coatings; etchand CMP stop layers protection and sealing layers of organic LEDs;organic solar cells; optical thin film filters; optical diffractivegratings and hybrid thin film diffractive grating structures; and highrefractive index abrasion resistant coatings